Gas turbine engines include compressor, combustor, and turbine sections. The rotational power generated by the turbine is delivered to driven equipment, such as electric generators and gas compressors, through an output shaft. One such gas turbine engine is discussed in U.S. Pat. No. 7,526,926 that discloses a drive system for a refrigeration compressor such as is used in a natural gas liquefaction plant, allowing the desired compressor speed and maximum turbine efficiency to be maintained throughout varying ambient temperature conditions. A gas turbine is used with an electric starter motor with drive-through capability located on a common drive shaft between the turbine and the compressor. A variable frequency drive is connected between the electrical power grid and the electric motor for smooth startups, but also to allow excess turbine mechanical power to be converted to electrical power by the motor operating as a generator, and delivered to the grid at the grid frequency.
The present disclosure is directed toward overcoming one or more of the problems discovered by the inventors.